﻿//----------------------------------------------
//            NGUI: Next-Gen UI kit
// Copyright © 2011-2014 Tasharen Entertainment
//----------------------------------------------

using UnityEngine;

/// <summary>
/// This script can be used to restrict camera rendering to a specific part of the screen by specifying the two corners.
/// </summary>

[ExecuteInEditMode]
[RequireComponent(typeof(Camera))]
[AddComponentMenu("NGUI/UI/Viewport Camera")]
public class UIViewport : MonoBehaviour
{
    public Camera sourceCamera;
    public Transform topLeft;
    public Transform bottomRight;
    public float fullSize = 1f;

    Camera mCam;

    void Start()
    {
        mCam = GetComponent<Camera>();
        if (sourceCamera == null) sourceCamera = Camera.main;
    }

    void LateUpdate()
    {
        if (topLeft != null && bottomRight != null)
        {
            Vector3 tl = sourceCamera.WorldToScreenPoint(topLeft.position);
            Vector3 br = sourceCamera.WorldToScreenPoint(bottomRight.position);

            Rect rect = new Rect(tl.x / Screen.width, br.y / Screen.height,
                (br.x - tl.x) / Screen.width, (tl.y - br.y) / Screen.height);

            float size = fullSize * rect.height;

            if (rect != mCam.rect) mCam.rect = rect;
            if (mCam.orthographicSize != size) mCam.orthographicSize = size;
        }
    }
}